The male co-pilot was taken to a hospital to be evaluated. Egan says he earlier was checked by a doctor who had been aboard the flight. She said she did not know whether he was admitted to the hospital and declined to release any more information about him.

The spokeswoman says the co-pilot was current on his required yearly medical evaluation.

KOMO-TV reports the incident happened about a half-hour before landing while the plane was on auto-pilot.

Egan says the pilot requested emergency landing priority as a safety precaution, to get priority handling for the medical issue.